Low-Temperature De-NOx Extruded Monolithic Catalysts Based on Highly Dispersive Mn-Ce Oxide Nanoparticles of Low Ce Content

Abstract

A facile strategy to produce low-temperature De-NOx extruded monolithic catalysts based on the highly dispersive Mn-Ce oxide nanoparticles of low Ce content is described. The design of the materials is based on dual supports composed of reduced graphene oxide and TiO2, which is made by Mn-Ce oxide nanoparticles well separated on the supports without any agglomeration. Compared to the catalysts with only TiO2 support, the specific surface area of the catalysts is significantly increased by 2.8 times. The temperature-programmed desorption analysis of NH3 shows that the number of Lewis acid sites increases; thus, the binding strength of the NH3 at the surface of the oxides is also increased. Through the temperature-programmed reduction of the H-2, the rate of the reduction reaction also increases. Thus, the efficiency of the overall De-NOx reaction increases to 90% with a lower Ce content of 40% at 250 degrees C and shows good stability at a high temperature of 300 degrees C. By using the above-mentioned catalysts, a honeycomb-type extruded monolithic product with De-NOx efficiency higher than 90% in the temperature range between 200 and 300 degrees C is made without any additional binders. This indicates a good formability, enough for the fabrication of the commercialized products.